Re-enable NavigateTest#testNavigateMany

Ran 100 times locally w/o flaking.  This does add @RetryOnFailure
to be consistent with the test above, which does this only a single
time.

BUG=516018

Change-Id: I233166bb2ca9004a02dd81a9a3b32cc5a72545f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893977Reviewed-by: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Yun Liu <yliuyliu@google.com>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711533}

chrome/android/javatests/src/org/chromium/chrome/browser/NavigateTest.java

@@ -164,10 +164,10 @@ public class NavigateTest {
     }
 
     @Test
-    @DisabledTest(message = "crbug.com/516018")
     @Restriction(UiRestriction.RESTRICTION_TYPE_TABLET)
     @MediumTest
     @Feature({"Navigation"})
+    @RetryOnFailure
     public void testNavigateMany() throws Exception {
         final String[] urls = mTestServer.getURLs("/chrome/test/data/android/navigate/one.html",
                 "/chrome/test/data/android/navigate/two.html",